The captcha.php library is very user-friendly and extremely easy to integrate into existing forms, because of its simple API. It nevertheless sports many configuration options, like multiple image modes and accessible alternative text riddles. It also has "AJAX" super cow powers and many sensible defaults to frustrate users less than other implementations. It prevents spambot access well, even with its relaxed defaults.
EasyPhpMassEmail is a PHP class that is intended for Web sites that need a simple solution for sending many email messages and do not have access to the PEAR packages for sending mass emails. The EasyPhpMassEmail class sends the email messages in batches and relies on an email queue page that reloads after each batch. By doing so, it is possible to send a large number of emails without problems using the mail() function and have a progress indication at the same time. The example files in the package demonstrate the use of the class.
DHCP Lease Query in PHP is a PHP class that will allow you to send DHCPLEASEQUERY packets to inquire about known leases from a remote DHCP server. It is similar in nature to ISC's OMAPI but without the hangs it creates, nor does it cause dhcpd to behave in a single-threaded fashion while talking to it. After all, it emulates an actual DHCP "helper" (relay agent) and, as such, all queries travel over IP. It is based on RFCs related to DHCP and follows the RFCs as closely as possible.
VAT Checker for EU countries is a simple PHP class to check the validity of a VAT number from the European Union countries. It provides a single function that accepts a VAT number and a 2-letter country abbreviation as input and returns a boolean value to indicate whether the number is valid.